The present invention relates to an acoustic fluid machine on the basis of acoustic resonance in an acoustic resonator.
There is a known acoustic fluid machine in which a piston is reciprocated axially with minute amplitude at high speed in a larger-diameter base of an acoustic resonator so that a gas is sucked at the upper end into the acoustic resonator and discharged with pressure change in the acoustic resonator.
The acoustic fluid machine is utilized by amplitude pressure change of acoustic standing waves generated by resonance with the piston that reciprocates axially with minute amplitude, and the piston in the base of the acoustic resonator is reciprocated at high speed by an actuator.
The structure is simple and malfunction is difficult to occur. The acoustic fluid machine is expected to be used widely in the future.
However, in the acoustic fluid machine, a gas is sucked and discharged only by the piston which vibrates minutely, and there is a basic problem that compression ratio and flow rate obtained is relatively small. To obtain high-pressure high-flow-rate, it is necessary to lighten the piston and to increase output of the actuator. But if the piston is lighten, strength will become poor, and if output of the actuator is increased, it will increase cost for manufacturing the actuator.